1. Field of the Invention
The present invention relates to a file systems used for storing data in digital processing systems, and more specifically to a flexible approach to store attribute information (meta-data) related to files of a file system.
2. Related Art
A file system generally provides for storing and retrieving (in general, accessing) files in/from a storage system (e.g., hard drive). Examples of such file systems include FAT (File Allocation Table) based file system, System5FileSystem (S5fs), etc., well known in the relevant arts.
There are generally various attributes associated with the files of a file system. Each attribute provides data defining the corresponding property of a file maintained by the file system. Examples of the attributes include a directory name/path at which the file is located, the name of the file, size/volume of the file, locations where the data corresponding to each of the files is stored, etc.
In a prior approach, a file system supports a fixed number of attributes, that too of pre-specified types. In general, these attributes are set to corresponding values (including possibly no character, if the value is unavailable at that time) when a file is created, and the values are updated appropriately over time.
However, there are often situations when it is desirable to add attributes, possibly of a type not previously supported in the file system. For example, it may be desirable to store attribute information related to backup time for some type of files, but such need may not exist for other files. In addition, such a need to store backup time may be recognized after the design/installation of the file system, and the prior approach noted above may not support the addition of such new attribute types (let alone attributes of pre-specified types).
What is therefore needed is a flexible approach to store attribute information (meta-data) related to files of a file system.
In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. The drawing in which an element first appears is indicated by the leftmost digit(s) in the corresponding reference number.